Tecumseh instructed his men to retreat in the event of his death. Johnson was severely wounded, and left the battle early on. The battle continued for at least an hour afterwords, when cries that Tecumseh had died caused the Indians to retreat. It seems likely this claim was just used for political gain. The accounts of Tecumseh's death are conflicting, to say the least. The book I'm using as reference has four pages of different ways he was said to have died. The book is A Sorrow in Our Hearts, and it was swell. Edit: Fun fact- Johnson's horse was also severely injured, but lived long enough to deliver him to the medical tent where it promptly died. Edit 2: First AskHistorians post, let me know if I goofed.